Radio transmission method and radio transmission device

ABSTRACT

A transmission process of control data is carried out simply and the reliability of transmission of the control data is improved. Data transmission among a plurality of communication stations is performed with a predetermined packet arrangement and transmission of the control data from a control station or a communication station is performed with the same predetermined packet arrangement.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.10/720,007, filed on Nov. 21, 2003, now U.S. Pat. No. Re. 41,497 issuedAug. 10, 2010, which application is a reissue of U.S. Pat. No.6,324,667, issued Nov. 27, 2001, the disclosures of which are herebyincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a radio transmission method and a radiotransmission device suitable for being applied to a case of transmittingvarious kinds of information by, for example, a radio signal for makingup a local area network (LAN) among a plurality of appliances.

2. Description of the Related Art

In the past, when a local area network is set up among a plurality ofvideo appliances, a personal computer device and its peripherals in anarrow range such as in a home, in an office and the like to make itpossible to transmit data which are dealt with by those appliances,there is a case where data transmission can be carried out by radiotransmission by connecting a radio signal transmitting/receiving deviceto each appliance instead of directly connecting respective applianceswith a signal cable or something.

By making up the local area network with the radio transmission, thereis no need for directly connecting among respective appliances withsignal cables, thereby making it possible to simplify a systemarrangement.

By the way, in a case where a local area network area is made up byusing more than three units of radio devices, it has such an arrangementin which one unit of radio devices is designated as a control stationand according to an indication by control data transmitted from thecontrol station, a transmission path is secured for carrying out datatransmission among respective appliances.

Here, a control channel, a control slot for transmitting control dataand the like have such an arrangement prescribed by a radio transmissionformat and are made up such that generally the control data and otherdata are strictly discriminated when they are transmitted, and there hasbeen a need that a receiving process of the control data and a receivingprocess of general transmission data are carried out by differentprocesses.

Also, because the control data is data for securing the transmissionpath, there is a need that the control data is surely transmitted torespective appliances, but actually, the control data are made to betransmitted under the same condition as that of the other transmissiondata. As a result, a transmission system needs to be set up so as totransmit all of the transmission data including the control data on atransmitting path with a high quality. However, with respect to thetransmission data except the control data, there is a case where atransmission error of, for example, video data, audio data and the likeare negligible, but in a case of a transmission error of the controldata, it is undesirable. Therefore, even in the case of transmitting thevideo data, the audio data and the like, there previously was a need forsetting a transmission path in accordance with the transmissioncondition of the control data.

SUMMARY OF THE INVENTION

In view of the above point, an object of the present invention is tosimply carry out the transmission process of the control data.

Also, another object of the present invention is to improve thereliability of the transmission of the control data.

According to first aspect of the present invention, there is provided adata transmission method in which data transmission among a plurality ofcommunication stations is carried out as data with a predeterminedpacket arrangement and the transmission of the control data from acontrol station for carrying out an access control is also made to becarried out by the same predetermined packet arrangement.

According to the first data transmission method of the presentinvention, the control data and the other data are transmitted with acommon packet arrangement so that a reception process of the controldata and the other data can be made common on a reception side.

According to a second aspect of the invention, there is provided a datatransmission method in which an error detecting code or an errorcorrecting code is added to data to be transmitted among a plurality ofcommunication stations before transmitting the data as well as an errordetecting code or an error correcting code is independently added to thecontrol data, which carries out the access control, before transmittingthe control data.

According to the second data transmission method of the presentinvention, it becomes possible to stringently add the error detectingcode or the error correcting code to the control data than to the otherdata.

According to a third aspect of the present invention, there is provideda data transmission method in which data to be transmitted among aplurality of the communication stations are transmitted as data which ismade a predetermined packet arrangement and the transmission of thecontrol data from the control station, which carries out the accesscontrol, is repeatedly carried out a plurality of times as the packetarrangement.

According to the third data transmission method of the presentinvention, it is possible to raise a possibility that the control datacan be correctly received on the reception side due to repeatedtransmission of the control data.

According to a fourth aspect of the present invention, there is provideda data transmission method in which when the control data is detected bycarrying out a decoding process of data in a header portion of a signalreceived by the communication station, a control process of acommunication based on the control data is carried out and when it isdetected that data other than the control data is transmitted, thedecoding process of data which is transmitted continuously to the headerportion is carried out and when the decoding processing can not becarried out, a resend demand is made to a transmission source station.

According to the fourth data transmission of the present invention, whenthe control data and the other data are transmitted as the same packetarrangement, each data can be properly processed and at the same time,when there is a case where the decoding of the received data can not becarried out, the data can be made to be transmitted again.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory diagram showing an example of a systemarrangement according to an embodiment of the present invention;

FIG. 2 is a block diagram showing a layer arrangement of a transmissiondevice according to an embodiment of the present invention;

FIG. 3 is a block diagram showing a layer arrangement according to anembodiment of the present invention;

FIG. 4 is a block diagram showing an example of information transmissionaccording to an embodiment of the present invention;

FIG. 5 is an explanatory diagram showing an example of transmission dataarrangement (example of one symbol packet) according to an embodiment ofthe present invention;

FIG. 6 is a flowchart showing a transmission process in a case oftransmitting only header information according to and embodiment of thepresent invention;

FIG. 7 is an explanatory diagram showing an example of the transmissionarrangement (example of 8 symbol packet) according to an embodiment ofthe present invention;

FIG. 8 is an explanatory diagram showing an example of a transmissiondata arrangement (example of 3 symbol packet) according to an embodimentof the present invention;

FIG. 9 is a flowchart showing the transmission process in a case oftransmitting the header information and data according to an embodimentof the present invention;

FIG. 10 is a flowchart showing a reception process according to anembodiment of the present invention;

FIG. 11 is an explanatory diagram showing an example of the transmissiondata arrangement according to another embodiment of the presentinvention;

FIG. 12 is a flowchart showing the transmission process according toanother embodiment of the present invention;

FIG. 13 is a flowchart showing the reception process according toanother embodiment of the present invention; and

FIG. 14 is an explanatory diagram showing an example of the transmissiondata arrangement according to a further embodiment of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereafter, an embodiment according to the present invention will beexplained with reference to the attached drawings.

In this embodiment, the present invention is applied to a system whichcarries out transmission and reception of video data, data for acomputer and the like in a home and the like. First of all, an outlineof a system arrangement of this embodiment will be explained withreference to FIG. 1. For example, as shown in FIG. 1, in a home where aplurality of rooms R1, R2, . . . R6 are provided, suppose that a videodeck 11 is installed in the room R1, a video printer 12 in the room R2,a personal computer device 13 in the room R5, and a television receiver14 in the room R6, respectively. At this time, there is an arrangementsuch that transmission devices 1,2,3 and 4 are connected to respectivedevices 11, 12, 13 and 14, and radio transmission of various kinds ofdata among respective devices among 11, 12, 13 and 14 can be carried outby the connected transmission devices 1, 2, 3 and 4, respectively.

For example, it is conceivable that a video program reproduced from avideo tape in the video deck 11 is transmitted to and received by thetelevision receiver 14, is transmitted to the personal computer device13 to take an arbitrary image therein, and is transmitted to the videoprinter 12 to print out an arbitrary static image. Also, a video dataprocessed by the personal computer device 13 is transmitted to the videoprinter 12 to print out the same, is transmitted to the video deck 11 tobe recorded in a video tape or the like and is transmitted to andreceived by the television receiver 14. Also, it is conceivable that avideo program as a television broadcast which is being received by atuner incorporated in the television receiver 14 is transmitted to thevideo deck 11 to be recorded in a video tape or the like, is transmittedto the personal computer device 13 to take an arbitrary image thereinand is transmitted to the video printer 12 to print out an arbitraryimage.

Here, an explanation will be made about arrangements of each of thetransmission devices 1-4 which are connected to respective devices11-14. Here, the transmission devices 1-4 are made to have a commonarrangement and a transmission device 20 shown in FIG. 2 shows the wholeof a device used as each of the transmission devices 1-4 making up thetransmission system. This transmission device 20 is made up bycomprising an antenna 21 for carrying out the transmission and thereception, and a radio processing unit 22 connected to the antenna 21for carrying out a radio transmission process and a radio receptionprocess, thereby making it possible to carry out a radio transmissionbetween the device and the other transmission devices. In this case, asa frequency for transmission and reception by the radio processing unit22 of this example, for example, a very high frequency band (forexample, 5 GHz band) is used and a frequency (channel) for transmissionand reception can be set in plural numbers. In this example, as for atransmission output, a relatively weak output is set and for example,when used indoors, an output to the extent of carrying out radiotransmission of several meters to several ten meters (concretely, outputto the extent of being able to transmit to as far as a neighboring room)is set.

Then, the transmission device 20 is made up such that a data convertingunit 23 is provided for carrying out data conversion of a signalreceived by the radio processing unit 22 and for carrying out dataconversion of a signal transmitted from the radio processing unit 22,and the data converted by the data converting unit 23 can be temporarilymemorized in a memory 24. This temporary memorization process by thememory 24 is used when a relay of a radio signal is carried out by thetransmission device 20, and after the memorized data is read out atpredetermined timing, converted again by the data converting unit 23 andsupplied to the radio processing unit 22 to carry out radiotransmission.

Also, there is an arrangement such that the converted data by the dataconverting unit 23 is supplied to processing devices (here, the videodeck 11, the video printer 12, the personal computer device 13 and thetelevision receiver 14) which are connected thereto through an interface25 as well as data supplied from the connected processing devices issupplied to the data converting unit 23 through the interface 25 so thatthe data can be subjected to a conversion process.

There is an arrangement such that respective units in the transmissiondevice 20 carry out processes based on control by a control unit 26which is made up of a microcomputer and the like. In this case, when asignal received by the radio processing unit 22 is a control signal, thereceived signal is supplied to the control unit 26 through the dataconverting unit 23 and the control unit 26 sets the respective units ina state indicated by the received control signal. Also, as for a controlsignal transmitted from the control unit 26 to other transmissiondevices, the control unit 26 is made to supply the control signaltherefrom to the radio processing unit 22 through the data convertingunit 23 to carry out the radio transmission thereof.

Meanwhile, the transmission system of this example assembles the systemby preparing a plurality of the transmission devices having thearrangement shown in FIG. 2 and is set such that one transmission deviceof them functions as a master (control station) for transmitting thecontrol data and the other transmission devices receive the controlsignal and function as a slave which is set to a state indicated by themaster. In this case, the transmission device of the master as thecontrol station is disposed at a position so that in principle it candirectly communicate with all the slaves in the system, thereby makingup a so-called star-type network.

The transmission system is made up by using an arbitrary number of theabove-mentioned transmission devices 20. For example, the transmissiondevice 20 is used as each of the transmission devices 1-4 of the systemshown in FIG. 1.

Next, in a case where the transmission system is made up as shown inFIG. 1, a transmission process arrangement in the transmission devicewill be explained. Here, an example will be explained of video data orthe like being transmitted from the video deck 11 connected to thetransmission device 1 in the room R1 to the television receiver 14connected to the transmission device 4 in the room R6.

The transmission process arrangement of this example is, as shown inFIG. 3, made up of an upper-rank layer 51, a link layer 52 and alower-rank layer 53, and an application process necessary fortransmission control and a process necessary for transmitting andreceiving of data between the appliances connected to the transmissiondevice and the transmission device correspond to the upper-rank-layer51. A process in which data supplied by control of the upper-rank layer51 is converted to data with a transmission arrangement as well asreceived data is converted to data for output by control of theupper-rank-layer 51 corresponds to the link layer 52. A process in whichdata supplied from the link layer 52 is subjected to a radiotransmission process as well as reception processed data is supplied tothe link layer 52 corresponds to the lower-rank layer 53, and a processto convert as well as amplify a frequency for transmission and receptionis included therein. Here, this example is characterized by the processin the link layer 52.

A transmission arrangement from the video deck 11 to the televisionreceiver 14 becomes an arrangement as shown in FIG. 4. Data such asvideo data and the like output by the video deck 11, which is a processdevice, is converted by an interface unit 25a of the transmission device1, then subjected to a coding process by a modem unit 23a correspondingto the data converting unit and transmitted as a radio signal with apredetermined frequency band by a radio signal processing unit 22a.

On the transmission device 4 side, this radio signal is subjected to areception process by a radio transmission processing unit 22b, subjectedto a decoding process by a modem unit 23b corresponding to the dataconverting unit, converted for output by an interface unit 25b and thensupplied to the television receiver 14 as a process device.

Here, although transmission of necessary data such as the video data andthe like is carried out between the transmission device 1 and thetransmission device 4, control data for setting its transmission path istransmitted from the transmission device of the master which is set tobe a control station. Also, there is a case where control data of somekind is transmitted between the transmission device 1 and thetransmission device 4. For example. when data transmission is to bestarted, a head portion of the transmission data is attached with anaddress of a transmission source and an address of a receiver as controldata and then transmitted. Further, when a need arises for relaytransmission by another transmission device between the transmissiondevice 1 and the transmission device 4, there is a case where controldata related to the relay transmission (for example, data fordesignating the relaying station) is transmitted.

When an explanation is made as to an arrangement of the transmissiondata among respective transmission devices, here, there is anarrangement such that the transmission path is set by an OrthogonalFrequency Division Multiplex (so-called OFDM modulation), in which anorthogonal modulation process is carried out to convert a time axis to afrequency axis at a time of transmission with a predetermined unit (forexample, one symbol packet) as a unit and on a receiving side, ademodulation process is carried out to convert the frequency axis of areceived signal to the time axis. Meanwhile, in the followingexplanation, information which is actually desired to be transmittedsuch as video data, audio data and the like will be described astransmission data in order to discriminate it from the control data.

The one symbol packet as a first unit at a time of transmitting data hassuch an arrangement as shown in FIG. 5. The example shown in FIG. 5shows a packet S₁ in a case of transmitting control data and here, onesymbol packet has a capacity capable of transmitting 77 bits at themaximum and first, a reference bit R with 4 bits is arranged to befollowed by header information with 35 bits indicating control data andfollowing the control data, a header CRC (Cyclic Redundancy Code:hereafter is referred to as CRC) with 32 bits is arranged. Lastly, atail bit T with 6 bits is arranged. In a case of transmitting only thecontrol data, only a signal of one symbol packet S₁ is transmitted.

The data having such an arrangement is generated by a process shown inthe flowchart of FIG. 6. That is, as a packeting process of controlinformation, a process to add the header information and the header CRCis carried out under the control of the control unit 26 (refer to FIG.2) in the transmission device (step 101), and after being packeted tothe state shown in FIG. 5 (step 102), the control information issupplied to the radio processing unit 22 side, which is a lower ranklayer, for transmission (step 103).

Next, an example of a case in which the control data is included in thehead portion of the transmission data will be shown in FIG. 7. Thisexample shows an example in a case of transmitting 8 symbol packets, inwhich a reference bit R with 4 bits is arranged at the head portion of afirst symbol packet S₁₁ to be followed by the header information with 35bits indicating the control data and following the control data, theheader CRC (Cyclic Redundance Code) with 32 bits, which is an errordetecting code of the control data, is arranged. Lastly, the tail bit Twith 6 bits indicating an end of the control data is arranged.Meanwhile, the control data at the time indicates that there is thetransmitted data.

Then, from a second symbol packet₁₂ on, as long as the transmitted datasucceeds, transmission data with 75 bits is arranged per one symbolpacket, and for the last symbol packet S₁₈, the transmission data isarranged for first half 38 bits and in succession, a CRC with 32 bits,which is a transmission data error detection code, is arranged andlastly, the tail bit T with 6 bits indicating an end of the transmissiondata is arranged. Meanwhile, the CRC in the eighth symbol packet S₁₈ maybe a CRC which is generated by including not only the transmission dataafter the second symbol packet S₁₂ but the data in the first symbolpacket S₁₁ (header information and the like).

Here, an example of the eight symbol packets is shown, but the number ofthe symbol packets is variable depending on the capacity of thetransmission data (however, there is a case where the maximum number ofthe packets is regulated). For example, as shown in FIG. 8, there is acase where the transmission data is composed of three symbol packets.That is, with respect to the first symbol packet₂₁, the control data orthe like is transmitted with the same arrangement as in the first symbolS₁₁ shown in FIG. 7, the transmission data is arranged in from a secondsymbol packet S₂₂ on and the CRC as the error detecting code for thedata and the tail bit T are arranged in the latter half of a thirdsymbol packet S₂₃, or the last packet.

Data in a case where the control data and the transmission data aremixed is generated by a process shown in the flowchart of FIG. 9. Thatis, after the process to add the header information which is the controldata and the header CRC is carried out under the control of the controlunit 26 (refer to FIG. 2) in the transmission device (step 111), aprocess to add the transmission data and its CRC is carried out (step112), these data are packeted to a state shown in FIG. 7 and FIG. 8 orthe like (step 113) and supplied to the radio processing unit 22 side,which is the lower rank layer (step 114), for transmission.

Next, a decoding process at a time of receiving a transmitted signalwhich is packeted to a state shown in FIG. 5, FIG. 7 and FIG. 8 will beexplained with reference to the flowchart in FIG. 10. First of all, theheader information of the packet received is decoded under the controlof the control unit 26 in the transmission device (step 121). Here, itis judged from the address for a receiver side included in the headerinformation whether or not the transmission is to this station (step122) and when it is judged that the transmission is addressed to anotherstation other than this station, the decoding process is interrupted andwaits until the next packet is received (step 123).

When the control unit 26 judges that the transmission is to this stationat step 122, it is judged whether or not it is possible to decode thetransmitted signal by an error detecting process (or error correctingprocess) which uses the header CRC and the like (step 124), and when thedecoding is judged impossible, a process of transmitting control datademanding that transmission source station, or the control stationtransmit again this packet is carried out (step 125).

When the control unit 26 judges it possible to decode the transmittedsignal at a step 124, it is judged from information indicated by thecontrol data if the received packet is a packet of only the control dataor a packet added with the transmission data (step 126), and when thepacket is the one with only the control data, the control data is passedto the upper rank layer (step 128) and when the packet includes thetransmission data, decoding of a transmission data portion is carriedout (step 127) and the decoded transmitter data is passed to the upperrank layer (step 128).

By transmitting the data having the above-mentioned packet arrangement,each transmission device performs processes of transmitting andreceiving the control data and processes of transmitting and receivingthe transmission data are carried out by a packet having a commonarrangement, and hence the control data and the other data can besubjected to a common process, thereby reducing a load on thetransmission device. Particularly, the decoding of the control data aswell as the transmission data can be carried out by a common processwith a sole decoding circuit, thereby making it possible to simplify anarrangement of the receiving system although separate processes of themare carried out individually in the past.

Also, because the error detecting code is independently added to onlythe control data in the header portion and further, the number of bitsof the error detecting code therefor is made to be comparatively a largevalue (that is, in the above-mentioned example, the header CRC with 32bits whereas the control data with 35 bits) compared with that of theoriginal data, a strong error detecting process and a strong errorcorrecting process can be performed, thereby making it possible toprevent erroneous transmission of the control data before it happens.Further, because the error detecting and correcting processes and thedecoding process can be carried out by the header portion alone, ajudgement whether or not the information is to this station can be madeby only a packet in the header portion. For example, when it is data tothe other station, ensuing processes of receiving and decoding of thepacket can be omitted.

Meanwhile, by carrying out the strong error detecting and correctingprocesses to the header portion, it becomes possible to surely transmitat least only the control data without unnecessarily improving qualityof a transmission path at a stage of designing the transmission path.That is, without making a packet size and the arrangement of the headerinformation portion a special arrangement for the control data ordesigning a transmission path of unnecessarily high quality, highreliable transmission can be realized with a form which is suited to anexisting packet format.

Meanwhile, in the above-mentioned embodiment, the control data is madeto be transmitted by one symbol packet only at the head, but the controldata may well be transmitted by a plurality of symbol packets. In thiscase, with respect to important control data, the same data may well betransmitted repeatedly a plurality of times. FIG. 11 is a diagramshowing an example of a packet arrangement of this case, in which areference bit R with 4 bits is arranged at the head of a first symbolpacket S₃₁ to be followed by the header information with 35 bitsindicating the control data and following the control data, the headerCRC with 32 bits, which is the error detecting code for the controldata, is arranged and lastly, the tail bit T with 6 bits is arranged.The arrangement of this first symbol packet S₃₁ is the same as that ofthe packet S₁ in the example shown in FIG. 5 of transmitting only onesymbol packet, in which only control data in the packet symbol S₃₁concludes the control information. Then, in this example, in both asecond symbol packet S₃₂ and a third symbol packet S₃₃, the same controldata is arranged as the header information, and the same header CRC isrepeatedly arranged. However, the reference bit R is not added to thesecond symbol packet S₃₂ and the third symbol packet S₃₃, and only thetail bit T is arranged in the third symbol packet S₃₃ other than in thefirst symbol packet S₃₁.

Data with the packet arrangement shown in FIG. 11 is generated by aprocess shown in the flowchart of FIG. 12. That is, as a packetingprocess of the control information, after the process to add the headerinformation and the header CRC to the first symbol packet S₃₁ (step 131)is carried out, a process to add the same information to the secondsymbol packet S₃₂ is carried out (step 132) and further, a process toadd the same information to the third symbol packet S₃₃ is carried out(step 133). Then, these three packets are packeted to states as animportant control packet shown in FIG. 11 (step 134), which is suppliedto the radio processing unit 22 side, which is the lower rank layer, fortransmission (step 135).

Next, a process on a side for receiving and decoding a signal whichrepeats the control information three times will be explained withreference to the flowchart in FIG. 13. First of all, the headerinformation in the first symbol packet S₃₁ is decoded under the controlof the control unit 26 in the transmission device (step 141) to befollowed by decoding of the header information in the second symbolpacket S₃₂ under the control of the control unit 26 in the transmissiondevice (step 142) and further, the header information in the thirdsymbol packet S₃₃ is decoded under the control of the control unit 26 inthe transmission device (step 143). Then, it is judged whether or notthe control data of all the control packet is correctly decoded (step144) and when all the control data are decoded, verification of an errorcorrected portion is carried out by a majority judgement of the threecontrol data under the control of the control unit 26 in thetransmission device (step 145), thereby supplying the control data whichis judged correct to the upper rank layer (step 146).

When it is judged that all the three header information is not decodedat step 144, it is judged whether or not the two header information canbe decoded (step 147) and when the two header information can bedecoded, the control data which decoded the two header information arecompared with each other to judge whether or not they coincide with eachother (step 148). Here, when they coincide with each other, the controldata are supplied to the upper rank layer (step 149). When there is nocoincidence at step 148, the control data are removed and are not usedfor the control.

When it is judged that decoding of the two header information can not becarried out at step 147, it is judged whether or not one headerinformation can be decoded (step 151), and when the one headerinformation can be decoded, the control data which decoded the oneheader information is temporarily used (step 152) and supplied to theupper rank layer (step 153). When it is judged that the headerinformation can not entirely be decoded, the received data at this timeis removed and is not used for the control (step 154).

By repeatedly transmitting the header information including the controldata, a possibility becomes higher of the important control data beingsurely received and decoded on the receiving side, thereby making itpossible to carry out the control process more positively. Meanwhile,here, the example of repeatedly transmitting the same header informationthree times has been explained, but there may well be an arrangement inwhich the header information is repeatedly transmitted a plurality oftimes other than three times.

Also, in the above-mentioned embodiment, an example of the packetarrangement in a case of making up the transmission panel with theOrthogonal Frequency Division Multiplex has been shown, but theembodiment can be applied to a packet arrangement in which the othertransmission system makes up the transmission path. For example, FIG. 14is a diagram showing an arrangement of a packet (frame) which istransmitted by a Time Division Multiplex (TDM) system, in which, in acase where one frame corresponding to the one packet in theabove-mentioned example is made up of 6 slots, the header informationand its CRC are arranged in a first slot of a first frame F₁ and thetransmission data is arranged in from the second slot on, and the CRCfor the transmission data or the like is arranged in the last slot(here, a fifth slot). Then, a next frame F₂ is allocated forcommunicating with the other communication (node) station.

Then, the receiving side decodes the header information in the firstslot of each frame, judges the control data as well as if there is thetransmission data in from the second slot on and the like. With such anarrangement being in place, the process according to the presentinvention can be applied to the arrangement in which the transmissionpath is set by the Time Division Multiplex system.

Also, in a case of a Code Division Multiplex (CDM) system, a portioncorresponding to the first packet (frame) is encoded and decoded byusing a specified code and at a time when it is judged that thetransmission data is included thereafter, by making data of all thepackets (frames) decoded, the process of the present invention can beapplied.

Also, the above-mentioned embodiment is applied to the radio local areanetwork in a home, but is also applied to the transmission control whenthe other transmission process is carried out.

Also, in the above-mentioned embodiment, an explanation has notparticularly been made about the contents of the control data making upthe header information, but there may well be transmitted control dataof any form. Also, with respect to the transmission source fortransmitting the header information, instead of a case where thetransmission device in the transmission source carrying out the datatransmission is made to carry out the transmission, a transmissiondevice which is set to be a control station (master) other than thetransmission device in the transmission source may well be made to carryout the transmission.

According to the first radio transmission method, the control data andthe other data are transmitted with the common packet arrangement, thereception of the control data as well as the other data can be subjectedto a common process on the reception side and hence the receptionprocess of the control data can be easily carried out without carryingout a specified process.

According to the second radio transmission method, in the first radiotransmission method, by adding the predetermined error detecting code orthe error correcting code to the data having the arrangement of thepacket transmitted among a plurality of the communication stations aswell as by independently adding the predetermined error detecting codeor the error correcting code to the transmission data transmitted withthe packet arrangement, it becomes possible to favorably transmit onlythe control data.

According to the third radio transmission method, it becomes possible tomore strictly add the error detecting code or the error correcting codeto the control data than to the other data, and to excellently transmitonly the control data as well as to surely control the transmissionwithin a net work system with the control data from the control station.

According to the fourth radio transmission method, the repeatedtransmission of the control data enhances the possibility of correctlyreceiving the control data on the reception side.

According to the fifth radio transmission method, in the fourth radiotransmission method, by individually adding the error detecting code orthe error correcting code to every one unit of the control datatransmitted a plurality of times, by individually carrying out the errordetecting process or the error correcting process at every one unit ofthe control data on the reception side and by carrying out the controlprocess by utilizing control data with no error, the favorable receptionprocess becomes possible based on the control data transmitted aplurality of times.

According to the sixth radio transmission method, in a case where thecontrol data and the other data are transmitted with the same packetarrangement or the like, when the received data can not be decodedalthough each data can appropriately be processed, they are made to betransmitted again, thereby making it possible to appropriately carry outthe reception process of the control data.

According to the first radio transmission device, the control data andthe other data are transmitted in the form of the common packetarrangement, the reception processes of the control data and the otherdata can be made common on the reception side, thereby making itpossible to simply carry out the reception process of the control datawithout carrying out a special process.

According to the second radio transmission device, in the first radiotransmission device, by carrying out the error detecting process or theerror correcting process based on the error detecting code or the errorcorrecting code added to the data having the packet arrangement as wellas by carrying out the error detecting process or the error correctingprocess based on the error detecting code or the error correcting codeindependently added to the control data included in the header portion,it becomes possible to carry out stringent error detection or errorcorrection processes to the control data as well as to more surelyreceive the control data than the other data.

According to the third radio transmission device, it becomes possible tomore stringently carry out the error detection process or the errorcorrection process to the control data than to the other data, to moresurely receive only the control data and to carry out the controlprocess of sure data transmission based on the control data.

According to the fourth radio transmission device, because the samecontrol data is repeatedly transmitted, a possibility becomes higher forthis transmitted control data to correctly reach the other radiotransmission device as well as a possibility becomes higher thattransmission from the other transmission device by the control of thisradio transmission device within the network system can be correctlycarried out, thereby making it possible to favorably control thetransmission control.

According to the fifth radio transmission device, in the fourth radiotransmission device, by individually adding the error detecting code orthe error correcting code by the control data processing unit to everyunit of the control data transmitted from the transmission processingunit a plurality of times, the error detecting process or the errorcorrecting process can be carried out on the reception side at everyunit of the control data, and a possibility becomes higher that thecontrol data can be more correctly received.

According to the sixth radio transmission device, in a case where thecontrol data and the other data are transmitted with the same packetarrangement or the like, when the decoding of the reception data can notbe carried out although each data is appropriately processed, acountermeasure can be taken by transmitting its data again.

Having described preferred embodiments of the present invention withreference to the accompanying drawings, it is to be understood that thepresent invention is not limited to the above-mentioned embodiments andthat various changes and modifications can be effected therein by oneskilled in the art without departing from the spirit or scope of thepresent invention as defined in the appended claims.

1. A radio transmission method, comprising the steps of: transmittingdata among a plurality of communication stations with a predeterminedpacket arrangement; transmitting control data from one of acommunication station of said plurality of communication stations and acontrol station with said predetermined packet arrangement; adding oneof a predetermined error detecting code and a predetermined errorcorrecting code to said data to be transmitted among said plurality ofcommunication stations with said predetermined packet arrangement; andadding independently one of an error detecting code and an errorcorrecting code to said control data transmitted with said predeterminedpacket arrangement.
 2. A radio transmission method, comprising the stepsof: transmitting data added with one of a first error detecting code anda first error correcting code among a plurality of communicationstations; and transmitting control data indicating a transmissioncontrol of said data, wherein said control data is independently addedwith one of a second error detecting code and a second error correctingcode.
 3. A radio transmission method, comprising the steps of:transmitting data among a plurality of communications stations with apredetermined packet arrangement; and transmitting control datarepeatedly from one of a communication station of said plurality ofcommunication stations and a control station a plurality of times withsaid predetermined packet arrangement; adding one of an error detectingcode and an error correcting code to each of a plurality of units ofsaid control data transmitted said plurality of times; performing one ofan error detecting process and an error correcting process on areception side, wherein each of said plurality of units of said controldata carries out a control process by utilizing said control data withno error.
 4. A radio transmission device, comprising: a transmissiondata processing unit for processing data transmitted between said radiotransmission device and another said radio transmission device with apredetermined packet arrangement; a control unit for judging whethercontrol data for an access control is included in a header portion ofsaid predetermined packet arrangement and for performing a correspondingcontrol process; and one of an error detection processing unit and anerror correction processing unit for performing one of a first errordetecting process and a first error correcting process by utilizing oneof a first predetermined error detecting code and a first predeterminederror correcting code, respectively, added to said data with saidpredetermined packet arrangement and at the same time for performing oneof a second error detecting process and a second error correctingprocess by utilizing one of a second predetermined error detecting codeand a second predetermined error correcting code independently added tosaid control data included in said header portion.
 5. A radiotransmission device for use in performing radio data transmissionbetween said radio transmission device and another said radiotransmission device under a control from a predetermined one of saidradio transmission devices, comprising: one of an error detectionprocessing unit and an error correction processing unit for performingone of a first error detecting process and a first error correctingprocess by utilizing one of a first error detecting code and a firsterror correcting code, respectively, added to data transmitted betweensaid radio transmission device and said another radio transmissiondevice and at the same time for performing one of a second errordetecting process and a second error correcting process by errorutilizing a second error detecting code and a second error correctingcode, respectively, independently added to control date for performingaccess control.
 6. A radio transmission method comprising: transmittinga control packet from a communication station or a control station;transmitting a data packet; and controlling to arrange each of saidcontrol packet and said data packet having a header field, the headerfield having a first field for error detecting or error correcting, saiddata packet further having at least one data field and a second fieldfor error detecting or error correcting, in which a structure of theheader field and the first field for error detecting or error correctingof said control packet is the same as that of the header field and thefirst field for error detecting or error correcting of said data packet,in which tail bits indicating a termination of information are arrangedafter the first field for error detecting or error correcting of thecontrol packet, and in which said control packet does not include thedata field.
 7. The method according to claim 6, in which the respectivefirst field for error detecting or error correcting is usable to detector correct an error or errors which occurred in the respective headerfield.
 8. The method according to claim 6, in which the second field forerror detecting or error correcting is for detecting or correcting anerror or errors which occurred in the data field.
 9. The methodaccording to claim 8, in which the control packet includes the tail bitswhich indicate a termination of information in the respective controlpacket.
 10. The method according to claim 9, in which the tail bits arearranged at an end of the first field for error detecting or errorcorrecting of the respective control packet.
 11. The method according toclaim 8, in which the data packet includes tail bits which indicate atermination of information in the respective data packet.
 12. The methodaccording to claim 11, in which the tail bits of the data packet arearranged after an end of the second field for error detecting or errorcorrecting of the respective data packet.
 13. The method according toclaim 8, in which the structure includes a size such that the size ofthe header field and the first field for error detecting or errorcorrecting is the same in said control packet and said data packet. 14.The method according to claim 6, wherein Orthogonal Frequency DivisionMultiplexing (OFDM) is used for the transmission.
 15. A radiotransmission apparatus comprising: a transmission device to transmit acontrol packet and to transmit a data packet, each of said controlpacket and said data packet having a header field, the header fieldhaving a first field for error detecting or error correcting, said datapacket further having at least one data field and a second field forerror detecting or error correcting, in which a structure of the headerfield and the first field for error detecting or error correcting ofsaid control packet is the same as that of the header field and thefirst field for error detecting or error correcting of said data packet,in which tail bits indicating a termination of information are arrangedafter the first field for error detecting or error correcting of thecontrol packet, and in which said control packet does not include thedata field.
 16. The apparatus according to claim 15, in which therespective first field for error detecting or error correcting is usableto detect or correct an error or errors which occurred in the respectiveheader field.
 17. The apparatus according to claim 15, in which thesecond field for error detecting or error correcting is for detecting orcorrecting an error or errors which occurred in the data field.
 18. Theapparatus according to claim 15, in which the structure includes a sizesuch that the size of the header field and the first field for errordetecting or error correcting is the same in said control packet andsaid data packet.
 19. The apparatus according to claim 15, in which thecontrol packet includes the tail bits which indicate a termination ofinformation in the respective control packet.
 20. The apparatusaccording to claim 19, in which the tail bits are arranged at an end ofthe first field for error detecting or error correcting of therespective control packet.
 21. The apparatus according to claim 15, inwhich the data packet includes tail bits which indicate a termination ofinformation in the respective data packet.
 22. The apparatus accordingto claim 21, in which the tail bits of the data packet are arrangedafter an end of the second field for error detecting or error correctingof the respective data packet.
 23. The apparatus according to claim 15,wherein Orthogonal Frequency Division Multiplexing (OFDM) is used forthe transmission.